Auto makers have said they may sue to block the plan.

The California Air Resources Board said that in the initial phase from 2009 through 2012, the plan calls for regulation requiring technology to reduce emissions by about 25 percent for cars and light trucks, and by about 18 percent for larger trucks and sport-utility vehicles.

When it is fully implemented after 2016, the recommended regulation would reduce emissions by up to 34 percent for cars and light trucks, and by 25 percent for larger vehicles.

In the initial phase, the new rule would add about $292 to the cost of each car and small truck, and about $308 to the cost of every large pickup and SUV. In the next phase, between 2013 and 2016, it would add an average of $626 per car and $955 per large pickup and SUV, the board said in a statement.

The California board's final reports came a day after the federal Environmental Protection Agency said it had certified Ford Motor Co.'s 2005 Escape as the first gasoline-electric hybrid SUV for sale in the United States. It met the agency's stringent new emissions standards.

Environmentalists said the board could have done more. They applauded the focus on making cars cleaner, but noted the board's plan does not take into account California's growth.

"It's disappointing that the air board didn't go further," said Russell Long, executive director of the Bluewater Network environmental group. "Emissions will not decrease because of the increase in vehicles on the road ... We need to reduce emissions on an absolute basis."